U.S. President Donald Trump threatened on Wednesday to impose a 50% tariff on all aircraft sold in the United States from Canada, escalating a dispute with Canadian Prime Minister Mark Carney in the latest jab in his trade war with the northern neighbor.

Trump issued the threat on Truth Social, his social media platform, coming on the heels of his threat last weekend to slap a 100% tariff on Canadian imports if Canada pursued an upcoming trade agreement with China.

Trump's threat, however, did not include specifics on when the tariffs would be applied, as Canada already had a deal in place, the Associated Press reported.

Trump stated in his post that the retaliatory action was a response to Canada's refusal to certify jets from Gulfstream Aerospace, which is headquartered in Savannah, Georgia.

He said that the U.S. would revoke the certification for all Canadian aircraft, including Bombardier, Canada's largest aircraft manufacturer.

"If this situation is not immediately rectified for any reason whatsoever, I will be imposing a 50% tariff on all aircraft coming into the United States, all aircraft from Canada," Trump stated in the post.

"I am revoking the certification for the Bombardier Global Express business jet by me," Trump added.

There are 150 Global Express aircraft registered and operational in the United States and operated by 115 operators, according to Cirium, an aviation analytics firm.

A spokesperson for Bombardier and Transport Canada did not immediately respond to requests for comment on Thursday evening.

The U.S. Department of Commerce imposed tariffs on Bombardier's commercial passenger jets in early 2017 during the Trump administration. At the time, the U.S. government argued that the Canadian company was selling its aircraft in the U.S. for less than cost.

The U.S. at the time alleged that Bombardier, based in Montreal, was selling its jets at artificially low prices by leveraging unfair government subsidies.

The U.S. International Trade Commission in Washington later ruled that Bombardier did not harm U.S. industry.

Bombardier has since focused on the business and personal jet markets.

Trump's threat to block access to the U.S. market would be a significant blow to the Quebec-based company.

Finance Minister Scott Besant warned Prime Minister Carney on Wednesday that public remarks about recent U.S. trade policies could backfire, coming ahead of an official review of the U.S.-Mexico-Canada Agreement (USMCA), a trade deal that shields Canada from the brunt of Trump's tariffs.

Carney dismissed Besant's claim during a phone call with Trump on Monday that he had retracted his remarks at the World Economic Forum (WEF).

Carney said he told Trump that his comments at Davos were sincere and that Canada planned to diversify its dependence on the U.S. through 12 new trade agreements.

Last week, at the WEF in Davos, Carney had criticized economic coercion by larger nations against smaller ones, without naming Trump.

Carney's remarks garnered widespread praise and attention, the AP reported.

Besides Bombardier, other major aircraft manufacturers in Canada include De Havilland Aircraft of Canada, which produces turboprop aircraft and aircraft for maritime patrol and surveillance, and European aerospace giant Airbus.

Airbus manufactures single-aisle A220 commercial aircraft and helicopters in Canada.

During the Biden administration, the U.S. International Trade Administration (ITA) emphasized the interdependence of the U.S. and Canadian aerospace industries, citing a 1980 World Trade Organization (WTO) agreement that "calls for the elimination of tariffs on civil aircraft, engines, flight simulators and related parts," according to the current U.S. Trade Representative (USTR) website.

Canada's Trade Representative describes the U.S. as the largest trading partner for its aerospace industry and the destination for a substantial portion of its exported aircraft, parts and space technology.

By NNP=Sung Ku Hong, Chief Correspondent / Special to this newspaper NNP info@newsandpost.com